The present invention relates generally to a method and apparatus for manufacturing molded products. More specifically, embodiments of the present invention relate to an open-pore molding process and apparatus for manufacturing molded products. In addition, embodiments of the present invention are directed to molded products, including floor mats, manufactured using processes of the present invention.
Open-pore or open cavity molding processes for manufacturing molded rubber or plastic products are known. In a typical prior art open cavity molding process, a single piece mold having a concave portion formed therein is filled with a liquid rubber or plastic material, and the mold is inserted in an oven to cure the material. After curing, the finished product is removed from the mold. These open cavity molding processes of the prior art are relatively inexpensive and are particularly useful for manufacturing substantially flat thin products including floor mats, such as those typically used in automobiles and other vehicles. In typical open cavity molding processes, a single color of material is used to make single color products.
Products manufactured using open cavity molding processes typically have one smooth side, formed from the top surface of the material in the mold, and one featured side having a number of contoured features formed therein by contours in the bottom surface of the concave portion of the mold. For typical floor mats manufactured using the prior art processes described above, the bottom surface of the floor mat is substantially smooth, and the top surface has a number of contours or features that provide a textured surface. For floor mats and other products, it is sometimes desirable to have features formed on the top and bottom surfaces of the products, and to provide products having multiple colors. While it is possible to produce such products using processes other than open cavity molding, such as injection molding, these other processes are typically more complex and therefore more expensive than open cavity molding. It is also sometimes desirable to incorporate fabric into a portion of the top surface of the product to provide, for example a carpeted section of a floor mat.
In one general aspect, the present invention features a molding process for producing a molded product using a mold having a lower plate and an upper plate. The molding process includes steps of filling a first cavity of the lower plate with a molding material of a first color, placing the upper plate on top of the lower plate such that a convex portion of the upper plate extends into the first cavity of the lower plate and contacts the molding material in the lower plate, and curing the molding material.
The convex portion of the upper plate can have a plurality of convex sections and a plurality of concave sections, and the convex portion of the upper plate can be placed in the material such that the convex sections contact the material and force the material to flow into the concave sections of the upper plate. The step of curing can occur before or after the step of placing. The method can further include a step of filling a second cavity in the lower plate with a liquid molding material of a second color. The step of filling the second cavity can be performed before the step of filling the first cavity. The method can include a step of adding carpet material to the molded product. The method can also include a step of clamping the upper plate to the lower plate.
Another general aspect of the present invention is directed to an apparatus for producing a molded product using a material. The apparatus includes a bottom plate having an upper mating surface. The upper mating surface has a cavity to receive the material. The cavity has bottom surface containing a plurality of concave areas to form contoured features in a first surface of the molded product. The apparatus can further include a top plate having a top surface and a bottom mating surface. The bottom mating surface can be constructed and arranged to mate with the upper mating surface of the bottom plate. The bottom mating surface can have a convex section arranged to extend into the cavity to contact liquid material in the cavity. A bottom surface of the convex section of the top plate can have a plurality of convex sections to contact the liquid material in the cavity to form features in a second surface of the molded product. The top plate can have a plurality of holes extending from the bottom surface of the convex section to the top surface of the top plate. The holes and the convex sections of the top plate can be constructed and arranged such that material in the cavity is forced into the holes by the convex sections. At least one of the convex sections on the top plate can be in the shape of a pyramid having four base edges forming a polygon, the polygon having four corner points, and one of the holes can be located at each corner point of the pyramid. The top surface of the top plate can have a concave section that captures material forced through the holes by the convex sections.
Another general aspect of the present invention is directed to an apparatus for producing a molded floor mat. The molded floor mat has an upper surface and a lower surface. The apparatus includes means for forming concave and convex features on the upper surface of the floor mat and means for forming convex features on the lower surface of the floor mat.
The means for forming concave and convex features on the upper surface of the floor mat can include means for molding a first part of the upper surface of the floor mat using a first color of material and means for molding a second part of the upper surface of the floor mat using a second color of material. The apparatus can further include means for adding carpeting to the upper surface of the floor mat.